Thuban/UI/application.py

# Copyright (C) 2001, 2002, 2003 by Intevation GmbH
# Authors:
# Jan-Oliver Wagner <[email protected]>
# Bernhard Herzog <[email protected]>
#
# This program is free software under the GPL (>=v2)
# Read the file COPYING coming with Thuban for details.

"""
Thuban's application object.
"""

__version__ = "$Revision$"

import sys, os
import os.path

import traceback

from wxPython.wx import *
from wxPython.lib.dialogs import wxScrolledMessageDialog

from Thuban.Lib.connector import Publisher
from Thuban.Lib.fileutil import get_application_dir

from Thuban import _
from Thuban.Model.session import create_empty_session
from Thuban.Model.save import save_session
from Thuban.Model.load import load_session
from Thuban.Model.messages import MAPS_CHANGED
from Thuban.Model.layer import RasterLayer
import Thuban.Model.resource

import view
import tree
import mainwindow

from messages import SESSION_REPLACED


class ThubanApplication(wxApp, Publisher):

    """
    Thuban's application class.

    All wxWindows programs have to have an instance of an application
    class derived from wxApp. In Thuban the application class holds
    references to the main window and the session.
    """

    def OnInit(self):
        sys.excepthook = self.ShowExceptionDialog
        self.splash = self.splash_screen()
        if self.splash is not None:
            self.splash.Show()
        self.read_startup_files()
        self.top = self.CreateMainWindow()
        self.SetTopWindow(self.top)
        if self.splash is None:
            self.ShowMainWindow()
        self.session = None
        self.create_session()
        return True

    def OnExit(self):
        """Clean up code.

        Extend this in derived classes if needed.
        """
        self.session.Destroy()
        self.session = None
        Publisher.Destroy(self)

    def read_startup_files(self):
        """Read the startup files."""
        # for now the startup file is ~/.thuban/thubanstart.py
        dir = get_application_dir()
        if os.path.isdir(dir):
            sys.path.append(dir)
            try:
                import thubanstart
            except ImportError:
                tb = sys.exc_info()[2]
                try:
                    if tb.tb_next is not None:
                        # The ImportError exception was raised from
                        # inside the thubanstart module.
                        sys.stderr.write(_("Cannot import the thubanstart"
                                         " module\n"))
                        traceback.print_exc(None, sys.stderr)
                    else:
                        # There's no thubanstart module.
                        sys.stderr.write(_("No thubanstart module available\n"))
                finally:
                    # make sure we delete the traceback object,
                    # otherwise there's be circular references involving
                    # the current stack frame
                    del tb
            except:
                sys.stderr.write(_("Cannot import the thubanstart module\n"))
                traceback.print_exc(None, sys.stderr)
        else:
            # There's no .thuban directory
            sys.stderr.write(_("No ~/.thuban directory\n"))

    def splash_screen(self):
        """Create and return a splash screen.

        This method is called by OnInit to determine whether the
        application should have a splashscreen. If the application
        should display a splash screen override this method in a derived
        class and have it create and return the wxSplashScreen instance.
        The implementation of this method in the derived class should
        also arranged for ShowMainWindow to be called.

        The default implementation simply returns None so that no splash
        screen is shown and ShowMainWindow will be called automatically.
        """
        return None

    def ShowMainWindow(self):
        """Show the main window

        Normally this method is automatically called by OnInit to show
        the main window. However, if the splash_screen method has
        returned a splashscreen it is expected that the derived class
        also arranges for ShowMainWindow to be called at the appropriate
        time.
        """
        self.top.Show(True)

    def CreateMainWindow(self):
        """Create and return the main window for the application.

        Override this in subclasses to instantiate the Thuban mainwindow
        with different parameters or to use a different class for the
        main window.
        """
        msg = (_("This is the wxPython-based Graphical User Interface"
               " for exploring geographic data"))
        return mainwindow.MainWindow(NULL, -1, "Thuban", self, None,
                                     initial_message = msg,
                                     size = (600, 400))

    def Session(self):
        """Return the application's session object"""
        return self.session

    def SetSession(self, session):
        """Make session the new session.

        Issue SESSION_REPLACED after self.session has become the new
        session. After the session has been assigned call
        self.subscribe_session() with the new session and
        self.unsubscribe_session with the old one.
        """
        oldsession = self.session
        self.session = session
        self.subscribe_session(self.session)
        self.issue(SESSION_REPLACED)
        self.maps_changed()
        if oldsession is not None:
            self.unsubscribe_session(oldsession)
            oldsession.Destroy()

    def subscribe_session(self, session):
        """Subscribe to some of the sessions channels.

        Extend this method in derived classes if you need additional
        channels.
        """
        session.Subscribe(MAPS_CHANGED, self.maps_changed)

    def unsubscribe_session(self, session):
        """Unsubscribe from the sessions channels.

        Extend this method in derived classes if you subscribed to
        additional channels in subscribe_session().
        """
        session.Unsubscribe(MAPS_CHANGED, self.maps_changed)

    def create_session(self):
        """Create a default session.

        Override this method in derived classes to instantiate the
        session differently or to use a different session class. Don't
        subscribe to channels here yet. Do that in the
        subscribe_session() method.
        """
        self.SetSession(create_empty_session())

    def OpenSession(self, filename, db_connection_callback = None):
        """Open the session in the file named filename"""
        # Make sure we deal with an absolute pathname. Otherwise we can
        # get problems when saving because the saving code expects an
        # absolute directory name
        filename = os.path.abspath(filename)
        session = load_session(filename,
                               db_connection_callback = db_connection_callback)
        session.SetFilename(filename)
        session.UnsetModified()
        self.SetSession(session)

        for map in session.Maps():
            for layer in map.Layers():
                if isinstance(layer, RasterLayer) \
                    and not Thuban.Model.resource.has_gdal_support():
                    msg = _("The current session contains Image layers,\n"
                            "but the GDAL library is not available to "
                            "draw them.")
                    dlg = wx.wxMessageDialog(None,
                                             msg,
                                             _("Library not available"),
                                             wx.wxOK | wx.wxICON_INFORMATION)
                    print msg
                    dlg.ShowModal()
                    dlg.Destroy()
                    break

    def SaveSession(self):
        save_session(self.session, self.session.filename)

    def maps_changed(self, *args):
        if self.session.HasMaps():
            self.top.SetMap(self.session.Maps()[0])
        else:
            self.top.SetMap(None)

    in_exception_dialog = 0 # flag: are we already inside the exception dialog?

    def ShowExceptionDialog(self, exc_type, exc_value, exc_traceback):
        """Show a message box with information about an exception.
    
        The parameters are the usual values describing an exception in
        Python, the exception type, the value and the traceback.
    
        This method can be used as a value for the sys.excepthook.
        """

        if self.in_exception_dialog:
            return
        self.in_exception_dialog = 1
        while wxIsBusy():
            wxEndBusyCursor() # reset the mouse cursor

        try:
            lines = traceback.format_exception(exc_type, exc_value,
                                            exc_traceback)
            message = "An unhandled exception occurred:\n%s\n" % exc_value+\
                    "(please report to " \
                    "http://thuban.intevation.org/bugtracker.html)"\
                    "\n\n\n"+\
                    "".join(lines)
            print message

            # We don't use an explicit parent here because this method might
            # be called in circumstances where the main window doesn't exist
            # anymore.
            dlg = wxScrolledMessageDialog(None, message,
                                        "Thuban: Internal Error")
            dlg.ShowModal()
            dlg.Destroy()

        finally:
            self.in_exception_dialog = 0
            # delete the last exception info that python keeps in
            # sys.last_* because especially last_traceback keeps
            # indirect references to all objects bound to local
            # variables and this might prevent some object from being
            # collected early enough.
            sys.last_type = sys.last_value = sys.last_traceback = None

1	# Copyright (C) 2001, 2002, 2003 by Intevation GmbH
2	# Authors:
3	# Jan-Oliver Wagner <[email protected]>
4	# Bernhard Herzog <[email protected]>
5	#
6	# This program is free software under the GPL (>=v2)
7	# Read the file COPYING coming with Thuban for details.
8
9	"""
10	Thuban's application object.
11	"""
12
13	__version__ = "$Revision$"
14
15	import sys, os
16	import os.path
17
18	import traceback
19
20	from wxPython.wx import *
21	from wxPython.lib.dialogs import wxScrolledMessageDialog
22
23	from Thuban.Lib.connector import Publisher
24	from Thuban.Lib.fileutil import get_application_dir
25
26	from Thuban import _
27	from Thuban.Model.session import create_empty_session
28	from Thuban.Model.save import save_session
29	from Thuban.Model.load import load_session
30	from Thuban.Model.messages import MAPS_CHANGED
31	from Thuban.Model.layer import RasterLayer
32	import Thuban.Model.resource
33
34	import view
35	import tree
36	import mainwindow
37
38	from messages import SESSION_REPLACED
39
40
41	class ThubanApplication(wxApp, Publisher):
42
43	"""
44	Thuban's application class.
45
46	All wxWindows programs have to have an instance of an application
47	class derived from wxApp. In Thuban the application class holds
48	references to the main window and the session.
49	"""
50
51	def OnInit(self):
52	sys.excepthook = self.ShowExceptionDialog
53	self.splash = self.splash_screen()
54	if self.splash is not None:
55	self.splash.Show()
56	self.read_startup_files()
57	self.top = self.CreateMainWindow()
58	self.SetTopWindow(self.top)
59	if self.splash is None:
60	self.ShowMainWindow()
61	self.session = None
62	self.create_session()
63	return True
64
65	def OnExit(self):
66	"""Clean up code.
67
68	Extend this in derived classes if needed.
69	"""
70	self.session.Destroy()
71	self.session = None
72	Publisher.Destroy(self)
73
74	def read_startup_files(self):
75	"""Read the startup files."""
76	# for now the startup file is ~/.thuban/thubanstart.py
77	dir = get_application_dir()
78	if os.path.isdir(dir):
79	sys.path.append(dir)
80	try:
81	import thubanstart
82	except ImportError:
83	tb = sys.exc_info()[2]
84	try:
85	if tb.tb_next is not None:
86	# The ImportError exception was raised from
87	# inside the thubanstart module.
88	sys.stderr.write(_("Cannot import the thubanstart"
89	" module\n"))
90	traceback.print_exc(None, sys.stderr)
91	else:
92	# There's no thubanstart module.
93	sys.stderr.write(_("No thubanstart module available\n"))
94	finally:
95	# make sure we delete the traceback object,
96	# otherwise there's be circular references involving
97	# the current stack frame
98	del tb
99	except:
100	sys.stderr.write(_("Cannot import the thubanstart module\n"))
101	traceback.print_exc(None, sys.stderr)
102	else:
103	# There's no .thuban directory
104	sys.stderr.write(_("No ~/.thuban directory\n"))
105
106	def splash_screen(self):
107	"""Create and return a splash screen.
108
109	This method is called by OnInit to determine whether the
110	application should have a splashscreen. If the application
111	should display a splash screen override this method in a derived
112	class and have it create and return the wxSplashScreen instance.
113	The implementation of this method in the derived class should
114	also arranged for ShowMainWindow to be called.
115
116	The default implementation simply returns None so that no splash
117	screen is shown and ShowMainWindow will be called automatically.
118	"""
119	return None
120
121	def ShowMainWindow(self):
122	"""Show the main window
123
124	Normally this method is automatically called by OnInit to show
125	the main window. However, if the splash_screen method has
126	returned a splashscreen it is expected that the derived class
127	also arranges for ShowMainWindow to be called at the appropriate
128	time.
129	"""
130	self.top.Show(True)
131
132	def CreateMainWindow(self):
133	"""Create and return the main window for the application.
134
135	Override this in subclasses to instantiate the Thuban mainwindow
136	with different parameters or to use a different class for the
137	main window.
138	"""
139	msg = (_("This is the wxPython-based Graphical User Interface"
140	" for exploring geographic data"))
141	return mainwindow.MainWindow(NULL, -1, "Thuban", self, None,
142	initial_message = msg,
143	size = (600, 400))
144
145	def Session(self):
146	"""Return the application's session object"""
147	return self.session
148
149	def SetSession(self, session):
150	"""Make session the new session.
151
152	Issue SESSION_REPLACED after self.session has become the new
153	session. After the session has been assigned call
154	self.subscribe_session() with the new session and
155	self.unsubscribe_session with the old one.
156	"""
157	oldsession = self.session
158	self.session = session
159	self.subscribe_session(self.session)
160	self.issue(SESSION_REPLACED)
161	self.maps_changed()
162	if oldsession is not None:
163	self.unsubscribe_session(oldsession)
164	oldsession.Destroy()
165
166	def subscribe_session(self, session):
167	"""Subscribe to some of the sessions channels.
168
169	Extend this method in derived classes if you need additional
170	channels.
171	"""
172	session.Subscribe(MAPS_CHANGED, self.maps_changed)
173
174	def unsubscribe_session(self, session):
175	"""Unsubscribe from the sessions channels.
176
177	Extend this method in derived classes if you subscribed to
178	additional channels in subscribe_session().
179	"""
180	session.Unsubscribe(MAPS_CHANGED, self.maps_changed)
181
182	def create_session(self):
183	"""Create a default session.
184
185	Override this method in derived classes to instantiate the
186	session differently or to use a different session class. Don't
187	subscribe to channels here yet. Do that in the
188	subscribe_session() method.
189	"""
190	self.SetSession(create_empty_session())
191
192	def OpenSession(self, filename, db_connection_callback = None):
193	"""Open the session in the file named filename"""
194	# Make sure we deal with an absolute pathname. Otherwise we can
195	# get problems when saving because the saving code expects an
196	# absolute directory name
197	filename = os.path.abspath(filename)
198	session = load_session(filename,
199	db_connection_callback = db_connection_callback)
200	session.SetFilename(filename)
201	session.UnsetModified()
202	self.SetSession(session)
203
204	for map in session.Maps():
205	for layer in map.Layers():
206	if isinstance(layer, RasterLayer) \
207	and not Thuban.Model.resource.has_gdal_support():
208	msg = _("The current session contains Image layers,\n"
209	"but the GDAL library is not available to "
210	"draw them.")
211	dlg = wx.wxMessageDialog(None,
212	msg,
213	_("Library not available"),
214	wx.wxOK \| wx.wxICON_INFORMATION)
215	print msg
216	dlg.ShowModal()
217	dlg.Destroy()
218	break
219
220	def SaveSession(self):
221	save_session(self.session, self.session.filename)
222
223	def maps_changed(self, *args):
224	if self.session.HasMaps():
225	self.top.SetMap(self.session.Maps()[0])
226	else:
227	self.top.SetMap(None)
228
229	in_exception_dialog = 0 # flag: are we already inside the exception dialog?
230
231	def ShowExceptionDialog(self, exc_type, exc_value, exc_traceback):
232	"""Show a message box with information about an exception.
233
234	The parameters are the usual values describing an exception in
235	Python, the exception type, the value and the traceback.
236
237	This method can be used as a value for the sys.excepthook.
238	"""
239
240	if self.in_exception_dialog:
241	return
242	self.in_exception_dialog = 1
243	while wxIsBusy():
244	wxEndBusyCursor() # reset the mouse cursor
245
246	try:
247	lines = traceback.format_exception(exc_type, exc_value,
248	exc_traceback)
249	message = "An unhandled exception occurred:\n%s\n" % exc_value+\
250	"(please report to " \
251	"http://thuban.intevation.org/bugtracker.html)"\
252	"\n\n\n"+\
253	"".join(lines)
254	print message
255
256	# We don't use an explicit parent here because this method might
257	# be called in circumstances where the main window doesn't exist
258	# anymore.
259	dlg = wxScrolledMessageDialog(None, message,
260	"Thuban: Internal Error")
261	dlg.ShowModal()
262	dlg.Destroy()
263
264	finally:
265	self.in_exception_dialog = 0
266	# delete the last exception info that python keeps in
267	# sys.last_* because especially last_traceback keeps
268	# indirect references to all objects bound to local
269	# variables and this might prevent some object from being
270	# collected early enough.
271	sys.last_type = sys.last_value = sys.last_traceback = None
272
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svn:keywords	Author Date Id Revision